THIS IS A NEW NEVER OPENED TransGo SK4L80E SHIFT KIT FOR GM 4L80E TRANSMISSIONS 1991-ON. 

HERE ARE SOME OF THE VEHICLES IT WILL WORK ON WITH THE 4L80E TRANSMISSION 1991 THRU 2005, 

• GMC YUKON/XL 5.3L - 6.0L
• HUMMER V-8
• CHEVROLET SUBURBAN 5.3L - 6.0L
• CHEVROLET TAHOE

THIS KIT IS A GREAT UPDATE TO ANY 4L80E TRANSMISSION AND INCLUDES A NEW EXTREAM QUALITY BOOST BUSHING WITH MATCHING BOOST VALVE AND CORRECTS / PREVENTS / REDUCES THESE OTHER PROBLEMS,

1. HIGH PRESSURE PARTS BREAKAGE
2. DIRECT CLUTCH BURNUP
3. SOFT 2-3 SLIDE-BANG 1-2
4. LOW PRESSURE DUE TO SOLENOID FILTER  BREAKUP
5. NO UPSHIFTS WITHOUT DIAGNOSTIC CODES
6. 3RD CLUTCH FAILURE
7. COMES WITH WIDE BOOST VALVE AND PRESSURE RELIEF VALVE